Method and apparatus for foam generating and distributing



Foam form/Loy Chamber i fad/77 Form/n57 v 8 f I. I .Mazem'a n e Foam Form/n57 Wafer [xv/er Chamber" Bra Um Rania/(77's M (/rya/zarz v Georye G. Urgu/rarz" R M. URQUHART ET AL Jan. 18, 1 93s.

METHOD AND APPARATUS FOR FOAM GENERATING AND DISTRIBUTING 2 Sheets-Sheet 2 Original Filed Oct. 18, 1952 me r mm WW 0 F 6 0 We #9 C r d 0 9 o G Ajlecfor UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR FOAM GEN- ERATING AND DISTRIBUTING Radclifle M. Urquhart, Philadelphia, and George G. Urquhart, Cynwyd, Pa.

Original application October 18, 1932, Serial No. 638,272. Divided and this application November 8, 1937, Serial No. 173,514

15 Claims. (01. 261-76) This invention relates to improvements in The tank i is connected through a pipe I, in methods and apparatus for generating and diswhich there is a valve 3, with an ejector chamtributing foam for extinguishing fires or for other her 4. Into this chamber there is introduced, purposes where a foam blanket may be required, through a pipe 5, a stream of water which for example, in checking evaporation from volaemerges from a nozzle 6 inside the chamber. 5 tile liquids. In accordance with the invention The water is forced in under suitable pressure a stream of gas is utilized as a foam inducing which is supplied by the city mains or by the agent, as distinguished from the conventional pump of a fire engine. As the water rushes out type of foam-forming method in which chemicals of nozzle 6, it causes the foam-forming material 10 producea gas within a solution containing a to be drawn in more or less regularly from the 10 foam-forming material. tank I for admixture with the water stream.

The present application is a division of appli- In order to provide a larger capacity the pipe 2 cation Serial No. 638,272, filed October 18, 1932. may be connected to a branch I in which there A principal object of the invention is to prois a valve 8 and this branch is'connected in turn vide compact, readily portable foam generating to an auxiliary source of the foam-forming malii equipment, especially adapted for mounting on terial. The mixture of water and foam-forming an automobile truck to be operated by the exmaterial passes from the ejector chamber 4, prefhaust gases therefrom or otherwise, and on ships erably through a conical passageway 9, into a pipe where the foam-forming equipment is to be in which is connected to a foam-forming chamzo operated by the stack gases or otherwise, as will ber ii. It is desirable to pass the foam-forming be more fully described later. mixture into this chamber through a conical Another object of the invention is to provide passageway I! in which there is a spiral I; or foam generating equipment which can be used other suitable baflie means which will cause turin the protection of oil tanks and the like. Anbulent flow of the mixture and insure good conother object of the invention is to reduce the tact with the gas, which is injected through pipe 25 expense of foam generation by avoiding the use M. The gas is preferably non-combustible, for of gas-producing chemicals while maintaining example, carbon dioxide, nitrogen, exhaust gas, the quality of the foam. flue gas, vapors of carbon tetrachloride, or other Variousother objects and advantages of the non-inflammable organic compound or the like.

80 invention will be apparent from the following However, for some purposes it is permissible to description, read in connection with the accomuse a gas having some oxygen content, or even panying drawings, in which; air itself. Application Serial No. 638,272 above Figure 1 is a vertical section through a prereferred to is concerned with the latter aspect ferred type of equipment; of this invention. It is obviously better, however,

Figure 2 is a vertical section through an alterto use a non-combustible gas for fire extinguish- 35 native form of the apparatus; ing purposes, as there will inevitably be some Figure 3 is a side elevation showing the instaldecomposition of the foam with release of gas. lation of the equipment on a motor truck; and The action taking place in the passageway I! Figure 4 is a side elevation, partly in section, may be described as mechanical subdivision of showing the equipment on a steam boat. the foam-forming mixture. This action is not 40 Referring first to Figure 1, reference numeral absolutely necessary for the present invention i indicates a tank adapted to contain an adebut it is advantageous. The entering gas is disquate supply of a foam-forming material. This tributed in the chamber ii under pressure which will usuallybe 'an aqueous solution of asecondary may be from 15 to 30 pounds per square inch,

extract of licorice, extract of tank bark, saponin, or any desired pressure, depending upon the 45 or other suitable substance. These are known throw which is desired from the foam nozzle. in the trade as "stabilizers. The invention is It is possible to introduce the gas at relatively not limited to the use of any particular type of low pressures (not lower than the nozzle outlet foam-forming material. It is sufiicient if the. pressure) but better results are obtained by forcmaterial has the capacity of being foamed by ing the gas in at higher pressures. The gas 50 injecting a gas into its solution or suspension. causes the formation of a copious foam which we When reference is made herein to foam-forming have found to be satisfactorily stable and fire material it is understood that this will usually resistant. be an aqueous solution, but suspensions or other The pressure of the gas is-sumcient in general as suitable materials may be used. to carry the foam from chamber ii through hose l5 and nozzle [6 to the desired distance. However, it is within thescope of the invention the pressure of the foam. The action taking place in the discharge end of the mixingchamber the necessary fine state of subdivision.

Referring to Figure 2, the foam-forming ma-' terial is'sup'plied from a tank I! through a valved line l8 into the inlet chamber of a pump i9. In the pump the foam-forming material, which is preferably a. dilute aqueous solution, is mixed with water entering the pump through a line 20.

The mixed water and foam-forming solution pass from the discharge chamber of the pump through a pipe 200. into the ejector chamber 2]. as in Figurel, is connected with a hose or pipe 22 which supplies an auxiliary amount of foamforming solution if required. Unless the auxiliary supply is needed, a valve 23 in line 22 will be closed and valve 24 in line 25-, connected to the discharge chamber of the pump, will be opened. In this case the pump will deliver the aqueous foam-forming material directly to the foam-forming chamber 26 for discharge through a hose 2611. It will be unnecessary to describe this chamber as it, and its connections, are identical with those shown in Figure 1.

Referring now to Figure 3, the device of the invention is shown as mounted on a motor truck .for actuation by the exhaust gases from the truck. A tank 21 is arranged on the truck to I carry a solution of the foam-forming material. This tank may, for example, have a capacity of about twenty gallons. In another compartment 28 there is stored a larger volume of liquid which may be water without foam-forming substance in it. This compartment may hold about one hundred gallons. The figures are given with reference to an installation on a three to five ton fire truck. Tank 21 is arranged to discharge through a line 28 in which there is a two-way valve 29. This valve communicates respectively with a pipe 30 which leads to the ejector chamber 3| and with a pipe 32 arranged for connection to an auxiliary supply of foam-forming material. Water is supplied to the ejector chamber 3! through a line 33 which can be put in communication with any suitable source of water supply as the pump 34 which takes suction from tank 28 A twoeway valve 35 is installed in line 33 for putting it into communication with the ejector chamber 3i or for shutting it off therefrom and connecting the line to hose 33a. The water and foam-forming material pass from the ejector through line 36 to foam-forming chamber 31. Exhaust gases for forming the foam are obtained from the exhaust manifold 38. There is arranged in this a valve 39 which can be operated from the dashboard or other suitable location. When the valve is closed, the exhaust gases will be diverted through branch pipe 40 into the inlet end of themixing chamber 31. The foam produced in the mixing chamber passes out, under pressure of the exhaust gas, through hose li andnozzle 42.

Referring to Figure 4, the installation is similar plied on. a steam to utilize a pump or other means to increase This,

to. thatshow'n in Figure 3 but is shown as ap- V V vessel. Flue gases from the stack are-diverted at least in part by closing a valve'lflthrough branch pipe 45 and pump 15a, into {the foam-forming chamber 46. The valve l'i'in line I5 is closed when'the deviceis ,nOtin operation. It will'not be necessary to describe thejremaining parts of the equipment since'they'are'identical with those shown in Figures 1 nd The following specific example the operation or the device: a

A solution of secondary extract of licorice is supplied in tank I, Figure 1. When a fire is to be; extinguishedor other use made of the foam-forming equipment, water is passed through line 5 under a pressure of, for example, 30 to pounds per square inch. After having opened valve 3 in line 2 the mixture ofwater and licorice extract is mechanically subdivided in chamber i3 and is subjected to the action of carbon dioxide passed into foam-forming chamber I I under a'pressure of about 25 pounds per square inch. Theseconditions will permit the use of a hose of at least feet in length and will, in most cases, give a throw of foam from the nozzle of about 75 feet.

It will be understood that theseconditions are given merely for illustration. Various changes and alternative arrangements may be made within the scope of the appended'clai'ms in which it is our intention to claim all novelty inherent in the invention as broadly as the prior art permits;

We claimz' will illustrate 1. Method of producing foam, comprising subjecting a foam-forming material to mechanical subdivision induced byturbulent; flow; injectand then withdrawing itat least partially by pressure of the gas.

2. Apparatus for producing foam, comprising means for holding a foam-forming material, means for withdrawing the same therefrom, means for mixing the material with water, means for imparting turbulence to the resultant mixture and means for injecting a stream of gas under pressure into the turbulent mixture.

3. Apparatus for producing foam; comprising means for holding foam-forming material, means for withdrawing the material therefrom by the ejection effect of a stream of water, means for commingling the withdrawn material with water, and means for'injecting gas under pressure into the resulting mixture.

4. Apparatus for producing foam, comprising means forsupplying a foam-forming material, means for passing a stream of water through a constricted opening, a channel receiving such stream of water and connected to the means for supplying the foam-forming solution, whereby the water withdraws the solution therefrom, means for exposing the resultant mixture to gas in a manner to cause commingling of said gas with said mixture, and means for increasing the surface of said mixture exposed to said gas.

5. Apparatus for producing foam, a tank for holding a foam-forming solution, an

comprising ejector chamber connected to the tank, a water gas line entering said foam-forming chamber, and a the foam produced in said chamber.

6. Method of producing foam, comprising in- I jecting water into a mixing zone, supplying foamforming material to the mixing zone, through the suction of the water stream, iniectingthe resulting mixture of water and foam-forming material into a foam-forming zone, supplying a gas under pressure to said foam-forming zone, discharging the foam formed therein by the pressure of the gas, and conveying the foam to the point at which itistobeused.

'1. Method according to claim 6 m which an additional amount of foam-forming material is supplied from an exterior source.

8. In combination with a conveyance driven by an engine producing inert gas, a container on the conveyance adapted to hold foam-forming material, means for taidng of! portions of such'material in a stream of water, means for interconnecting the stream of water carrying foam-forming material with the inert gas from the engine. means for delivering the inert gas under pressure into said stream to produce foam therefrom,

and means for conveying the foam to the point of utilization.

9. In combination with a motor truck, a container thereon for foam-forming material, a water pump, an ejector, means connecting the water pump with the ejector and the container, a second ejector, means for passing the mixture of water and foam-forming material to. said second ejector, means for introducing a gas under pressure into said second ejector, and means for conveyingthe foam to the point of utilization.

10. Method of producing foam comprising introducing into a continuous stream of water under pressure, a suitable quantity of a foam-forming substance, subjecting the combined materials to mechanical subdivision induced by turbulent flow, passing the subdivided materials to a foam-forming zone, maintaining the subdivided condition of the materials while injecting thereinto a stream of gas under pressure from an outside source and withdrawing the resultant foam.

11. Apparatus for producing foam, comprising means for supplying a foam-forming material, means for passing a stream of water through a Patent No 2,106,01

hose connected to receive and discharge constricted opening, a chamber receiving such stream of water and connected to the means for supplying the foam-forming solution, whereby the water withdraws the solution therefrom, means for ejecting the resulting liquid at high velocity from a nozzle in such manner as to impart a high degree of turbulence to the body of said stream of liquid, thereby finely subdividing the same, and means for entraining a gas into and by means of the resulting stream of subdivided liquid.

12. Method of producing a fire-extinguishing foam which comprises ejecting one or more high velocity. streams of liquid from. a corresponding number of nozzles in such manner as to impart a high degree of turbulence to the body of 'saidstream of liquid, thereby finely subdividing the same, and entraining gas into and by means of the resulting streamof subdivided liquid in the presence of a foam-promoting agent.

13. Method of producing a fire-extinguishing foam which comprises producing a dispersed stream of liquid and aspirating a gas into said dispersed stream, in the presence of a foam promoting agent, and increasing the pressure of the resultant mixture by means of a pump.

14. Method of producing a fire-extinguishing foam which comprises flowing a liquid from a source of supply toward a point of discharge, in-

troducing into said liquid a foam-promoting agent, shaping said flowing liquid into an ejecting stream of dispersed foam in the presence of a gas whereby said stream acts to aspirate the gas and to cause a mingling of said liquid and gas as they move toward the point of discharge.

15. Apparatus for producing foam, comprising a channel, means for supplying a foam-promoting material to said channel, means for passing a CERTIFICATE OF CORRECTION January 18, 1958.

RADCLIFFE a. URQUHART, ET AL.-

It is hereby certified that error appears in the printed of the above numbered patent requiring correction as follows: coltunn, line 52, claim 1h, for the word "foam" read form; and Letters Patent should be read with this correction therein specification Page 3, second that the said that the same may conform to the record of the case in the Patent Office. Signed and sealed this 27th day of September, A. D. 1938.

(Seal) Henry Van Arsdale Acting Commissioner of Patents. g

gas line entering said foam-forming chamber, and a the foam produced in said chamber.

6. Method of producing foam, comprising in- I jecting water into a mixing zone, supplying foamforming material to the mixing zone, through the suction of the water stream, iniectingthe resulting mixture of water and foam-forming material into a foam-forming zone, supplying a gas under pressure to said foam-forming zone, discharging the foam formed therein by the pressure of the gas, and conveying the foam to the point at which itistobeused.

'1. Method according to claim 6 m which an additional amount of foam-forming material is supplied from an exterior source.

8. In combination with a conveyance driven by an engine producing inert gas, a container on the conveyance adapted to hold foam-forming material, means for taidng of! portions of such'material in a stream of water, means for interconnecting the stream of water carrying foam-forming material with the inert gas from the engine. means for delivering the inert gas under pressure into said stream to produce foam therefrom,

and means for conveying the foam to the point of utilization.

9. In combination with a motor truck, a container thereon for foam-forming material, a water pump, an ejector, means connecting the water pump with the ejector and the container, a second ejector, means for passing the mixture of water and foam-forming material to. said second ejector, means for introducing a gas under pressure into said second ejector, and means for conveyingthe foam to the point of utilization.

10. Method of producing foam comprising introducing into a continuous stream of water under pressure, a suitable quantity of a foam-forming substance, subjecting the combined materials to mechanical subdivision induced by turbulent flow, passing the subdivided materials to a foam-forming zone, maintaining the subdivided condition of the materials while injecting thereinto a stream of gas under pressure from an outside source and withdrawing the resultant foam.

11. Apparatus for producing foam, comprising means for supplying a foam-forming material, means for passing a stream of water through a Patent No 2,106,01

hose connected to receive and discharge constricted opening, a chamber receiving such stream of water and connected to the means for supplying the foam-forming solution, whereby the water withdraws the solution therefrom, means for ejecting the resulting liquid at high velocity from a nozzle in such manner as to impart a high degree of turbulence to the body of said stream of liquid, thereby finely subdividing the same, and means for entraining a gas into and by means of the resulting stream of subdivided liquid.

12. Method of producing a fire-extinguishing foam which comprises ejecting one or more high velocity. streams of liquid from. a corresponding number of nozzles in such manner as to impart a high degree of turbulence to the body of 'saidstream of liquid, thereby finely subdividing the same, and entraining gas into and by means of the resulting streamof subdivided liquid in the presence of a foam-promoting agent.

13. Method of producing a fire-extinguishing foam which comprises producing a dispersed stream of liquid and aspirating a gas into said dispersed stream, in the presence of a foam promoting agent, and increasing the pressure of the resultant mixture by means of a pump.

14. Method of producing a fire-extinguishing foam which comprises flowing a liquid from a source of supply toward a point of discharge, in-

troducing into said liquid a foam-promoting agent, shaping said flowing liquid into an ejecting stream of dispersed foam in the presence of a gas whereby said stream acts to aspirate the gas and to cause a mingling of said liquid and gas as they move toward the point of discharge.

15. Apparatus for producing foam, comprising a channel, means for supplying a foam-promoting material to said channel, means for passing a CERTIFICATE OF CORRECTION January 18, 1958.

RADCLIFFE a. URQUHART, ET AL.-

It is hereby certified that error appears in the printed of the above numbered patent requiring correction as follows: coltunn, line 52, claim 1h, for the word "foam" read form; and Letters Patent should be read with this correction therein specification Page 3, second that the said that the same may conform to the record of the case in the Patent Office. Signed and sealed this 27th day of September, A. D. 1938.

(Seal) Henry Van Arsdale Acting Commissioner of Patents. g 

